Air-compressor.



H. WILOOX & F. BRABSON.

AIR COMPRESSOR. APPLIHATION FILED APR. 1 1908.

915,815. Patented Mar. 23, 1909.

2 SHEETS-SHEET 1.

H. WILGOX & F. BRABSON.

AIR COMPRESSOR.

APPLICATION FILED APR. 1, 1908.

915,815. Patented Mar.23,1909.

2 SHEETS-SHEET 2.

HENRY WILCOX AND FRANK BRABSON, OF NEWARK, NEW JERSEY.

AIR-COMPRESSOR;

Specification of Letters Patent.

Patented March 23, 1909.

Application filed. April 1, 1908. I Serial N0. 424,568.

To all whom it may concern:

Be it known that we, HENRY \VILcox and FRANK BRABSON, citizens of the United States of America, and residents of Newark, county of Essex, and State of New Jersey, have invented certain new and useful Improvements iIIAiI'fCOHIPI'QSSOI'S, of which the following is-a specificatlon.

Our invention relates to improvements in air compressors, particularly that type thereof especially adapted and intended for the inflation of pneumatic tires, the operation of power whistles on motor boats, and like serv ice where a compressor of moderate capacity working to moderate pressures is desired.

Our invention consists in the novel mechanism of the compressor.

The objects of our invention are, to improve and simplify compressors of the type referred to, and to provide a compressor which is simple, extremely compact, relatively light, ca able of operation .at' high speeds, easy an cheap to manufacture, and

free from liability to derangement. I In the accompanying drawings we illustrate certain forms of compressor embodying our invention. I

In said drawings: Figure 1 shows a front elevation of one of said compressors; Fig. 2 shows a front view of the frame plate and attached parts, the casing and compression cylinder having been removed; Fig. 3 shows a section through the axes of the cylinder and driving shaft; Fig. 4 shows a transverse section of the pump through the center of the cylinder; Fig. 5 shows an elevation of that side of the cylinder which faces the frame plate; Fig. 6 shows a side elevation of an alternative form of pump; Fig.7 shows an elevation of the frame plate and attached parts,

with the cylinder removed; Fig. 8 shows a section of the pump through the axes of the cylinder and driving shaft; Fig. 9 shows a detail section through one of the pistons; Fig 10 a detail section through the discharge valve; Fig. 11 a perspective view of the admission valve; Fig. 12 a detail elevatlon of the valve in the partition at the center of the cylinder; and Fig. 13 shows in elevation and partial section, means for mounting the pump to be driven by friction from an engine fly wheel.

Referring first to Figs. 1-5 inclusive, 1

designates'a frame plate having lateral extensions 2, 2 provided with brackets 3, 3 forming outer heads for the cylinder 4. This frame plate 1 has also a bearing for the driving shaft 5. Within the'cylinder 4 are two pistons 6, 6 comprising front and rear heads connected by ribs 7. These pistons work toward each other so that no cylinder head is required between them; and the cylinder is provided with an inlet valve 8 and an outlet valve 9, the latter provided with a connection 11 for a flexible tube and provided also with a connection for a pressure gage 12. Driving shaft 5 is providedwith a crank pin 13 projecting from a disk 13 rigidly mounted on shaft 5; and to this crank pin is rigidly secured another disk 14.

rovided withan opposite crank pin. 15.

onnccting rods 16 are mounted upon these crank pins and are. provided wlth right angled ends fitting into sockets in the rear ends of pistons'o these right angledportions of the connecting. rods workin in slots 17 'in that side of the cylinder which faces the frame plate .1. It will be obvious that as the crank shaft is rotated, the pistons are alternately se )arated (air being then drawn in through vaive 8) and moved toward each other, so compressing air between them and forcing it out through the discharge valve 9.

The two disks 13 and 14 serve as guides for the connecting rods, permitting the bearing surface of the connecting rods on these crank pins to be much shorter than would otherwise be permissible and so making the crank mechanism very compact. By this construction we obtain all the advantages of two cylinders and two pistons, while needing only a. single inlet valve and a single discharge valve. Moreover, the pistons balance each other as to inertia and other reactions, since. they reciprocate in opposite directions, and'since they reciprocate along the same axial line.

To prevent entrance of dust into the mechanism, we preferably cover the cylinder and the face of the frame plate 1 with a casing 18. The cylinder ibeing made of thin tubing, we provide it near the center with a reinforcing ring 19, in function integral with said cylinder, and in this ring are threaded openings into which screw the bonnets of valves 8 and 9. Packing 20 is customarily provided between the anges of these bonnets and the casing, to make a tight joint.

It will be apparent that as the shaft 5 is rotated air is alternately drawn into the cylinder and Compressed between the pistons and forced out through valve 9. There being only two valves, leakage of air is re duccd to a minimum and owing to the perfect balancing of the two pistons the pump vided with extensions 24fitting into'sockets Since, ac-

in the rear ends of ,the pistons. cording to this construction, the )istons move in the same direction, the valve arrangement employed in Figs; 1-5 inclusive is not practicable, and the admission valves 25 are located in the pistons themselves. Also there is a partition 26, functionally forming a part of the cylinder, and located between the pistons; andto this partition is connected a discharge valve 27 provided with a valve plug 28 and with a connection 29 for a flexible tube; also a connection for a pressure gage 30.. In the partition 26 is avalve chamber 32 containing a disk valve 33 )rovided with-.a central guide stem 34:

wor iingthrough central orifices in disks 35 at the ends of the valve chamber 32. This guide stem is slotted lengthwise, as indicated particularly in Figs. 10 and 12, to permit free passage of air into valve chamber 32 and so past the discharge valve. It will be clear that as the driving shaft rotates. the pistons are moved back and forth alternately. As either piston moves toward the central partition, the air compressed before it moves the valve 33 to the opposite side of the partition, so permitting free passage of air from in front of such piston past the discharge valve; and when the other piston moves toward the partition the position of the valve 33 is automatically reversed by the action of the air.

The driving shaft 5 of the pumps illustrated, may bedriven in any suitable man ner. In Fig. 13 we have indicated means for driving said shaft by friction from the fly wheel of the engine. 36 designates a friction wheel mounted upon shaft 5 and adapted to be moved into and out of driving contact with the fly wheel 37 of an engine. The entire compressor is mounted upon a rocking frame 38 pivoted at 39 and a spring 40 tends to press the pump toward the fly wheel 37 and therefore to press the friction wheel 36 against said fly wheel. When it is not desired. to have thepump operating during-the rotation of fly wheel 37, retracting means,

such asa screw 41, is operated to draw and hold the rocking frame 38 back so that friction wheel 36 is not in contact with said ny wheel.

It is obvious that tle pump above described may be used for 1 umping gases other than air; also that while it is especially suitable for use as a tire inflating pump, it may be used fbr compressing air into a tank, or for operating a power whistle or other purpose for which small compressors are commonly used. Likewise, it will be obvious that the pump might be used for pumping liquids; suitable modifications being made preferably in the valves and passages, although the valvcs and passages shown will permit liquid to be used in the pump shown.

. In the pumps herein described we will com- -inonly regulate the size of the clearance space or spaces so that the pump is incapab e of )ummw be'ond a safe )rcssure thercbv l s i need of a relief valve is obviated.

Suitable means may be provided for lubricating the pistons. in the pump shown in Figs. 1-5 inclusive, we have shown for this purpose oil cups 4-2 so located that the pistons override the ports of the oil cups when they reach the outer ends of their strokes? The pistons are provided with the usual cup packings 13. Since these pistons compress toward the middle of the cylinder, the outer heads of the cylinder need not be tight, there never being any air pressure upon them.

What we claim 1s:--

1.. A pump such as described, comprising in combination. a cylinder, opposed pistons therein, a driving shaft located to one side of and at right angles to said cylinder and at a point intermediate the ends thereof, said shaft provided with opposed crank pins, connecting rods mounted on said crank pins and extending in opposite directions from the shaft toward the ends of said cylinder and working through slots in said cylinder, engaging said pistons to reciprocate the same toward. and from each other, and admission and discharge valves.

2. A pump such as described com )risin 1n combinatimi a frame plate having atera extensions, a cylinder secured to said frame plate, a driving shaft mounted in a bearing in said frame plate, crank mechanism operated by said shaft and arranged to reciprocate said pistons and located within a recess of said frame plate and. between said plate and cylinder, and con'iprising connecting rods outside of said cylinder and connected to said pistons near the rear ends thereof, and admission and discharge valves.

3. A pump such as described comprising in combination a cylinder provided with slots on one side, pistons within said cylinder hai ing sockets opposite said slots, a frame cured, to said cylinder, a crank shaft having hearing in said frame, means operated by rotation of said shaft for reciprocating said pistons comprising connecting means fit! within said sockets and working in said cylinder .slots, and admission and discharge valves.

4. A pump such as described comprising 5 in combination a frame, a cylinder connected thereto, opposed pistons within said cylinder, a driving shaft having a bearing in said frame, a crank pin carried by said shaft, a disk rigidly secured to said crank pin and 10 carrying an o posite crank pin', connecting rods connecte to said crank pins and pistons and adapted to be guided by said disk, and admission and discharge valves.

'5. A pump such as described comprisin 5 in combmation a frame, a cylinder connecte thereto, opposed pistons within said cylinder "a driving shaft havin a bearing in' said frame, a disk on said shaft provided with a crank pin, another disk rigidly secured to 2 said crank pin and carrying an opposite crank pin, connecting rods connected to crank pins 3 and pistons and arranged to be guided by said disks, and admission and discharge valves.

6. A pumpsuch as described comprisin 25 in combination a frame, a cy dericonnect thereto, op osed pistons within said cylinder, a driving s aft, crank mechanism operated thereb for operating said pistons, located to one si e of said cglinder admission anddis- 3o charge valves, an a casing surmundingsaid cylinder and connected to the frameso as to form a closed chamber inclosing said cylinder and crank mechanism.

In testimony where'ofwe have signed this 35 specification in the presenceof two subscribing witnesses. I HENRY 'WILCOX. FRANK BRABSON. Witnesses H. M. MARBLE, FRANK E. RAFFMAN. 

